Water wall boiler



April yB, 1937.

G w. HEALD ET AL WATER WALL BOILER Fiied sept. 9, 1955 s sheets-sheet@ April 6, 1937- v G. w. HEALD E1- Al. 2,075,985 WATER` WALL BOILER Filed Sept. 9, 1935 3 Sheets-Sheet 2 Patented Apr. 6, 1937 WATER WALL BOILER f .l

George W. Heald and Audrey J. Popham,

Chicago, Ill.

Application September 9, 1935, Serial No. 39,893

6 Claims.

This invention-relates to boilers, and has to do with water tube boilers provided with water walls. It is an object of our invention to provide a boiler structure embodying a water tube boiler provided with water walls, such boiler being of high efficiency, exceptionally compact construction and low head-room, and rapid steaming.

A further object is to provide a boiler of the character stated' havingwater walls included in 1o the water circulatory system and cooperating with certain of ,the other tubes of the boiler structure to denne a combustion space of considerable volume so disposed that the boiler as a whole has exceptionally low head-room. 15 Further objects and advantages of our invention will appear from the detail description.

In the drawings: i

Figure l1 is a front view, partly broken away and in section, of a boiler structure embodying 20 our invention, thebroken-away portion of this figure being sectioned substantially on line I-I Figure 2 is a sectional view taken from front to back of the boiler structure substantially in the 25 plane of line 2- 2 of Figure 1;

Figure 3 is a fragmentary sectional view of the boiler taken from front to back thereof substantially in the plane of line 3--3 of Figure l, parts being broken away and parts being omitted for 30 clearness of illustration; and

Figure 4 is a fragmentary vertical sectional view through the boiler from lfront to back thereof, taken substantially in the plane of line 4 5 of Figure 1, parts being omitted for clearness of 35 illustration. f i

The boiler structure, in its entirety, comprises the boiler proper and the setting therefor, includying the furnace. The setting S may be of any suitable or preferred type and includes a furnace, 40 dening a combustion chamber I beneath which extends a grate 2 adjacent the rearward endo! which a bridge wallI 3 extends transversely of the combustion chamber. The bridge wall and the f grate and adjacent portions-oi! the furnace define 4 5 the re-box l, to which fuel may be supplied by a stoker 5- of suitable type, or in any other suitablemanner. The particular manner of supplying fuel to the furnace is not of the essence of our invention, nor is the type of fuel used, it be- 50 ing understood that any suitable fuel supplied to the furnace in any well known or suitable manner may be utilized. The furnace is, in general, cubiform, side walls 6 thereof defining the sides of the combustion chamber I.

55 The boiler proper is suitably supportedin the (Gl.l 122-336) v setting S. 'Ihis yboiler comprises two upper steam and water drums 'I and 8 disposed adjacent the front and the rear of the furnace, respectively,

and a lower mud drum 9 disposed in rear of bridge wall 3 and in'substantial vertical alignment with drum 8. Drums 'I and 8 are connected by a bank of water tubes I0 opening into these drums below theY normal water line therein, indicated in Figure 2, and drums 8 and 9 are connected by a bank of tubes I I. Mud drum 9 is connected to drum 1 -by a bank of tubes I2, these tubes being of approximately L-shape lengthwise and having their lower arms disposed vertically and substantially parallel to tubes II of the rear bank. The upper arms of tubes I2 are inclined upwardly and forwardly toward drum l, as shown in Figure 2, and these arms are alternately depressed so that each is vertically spaced from the next adjacent arm, as shown. The three'banks of tubes thus connectthe drums in a ring flow circuit, this arrangement being conducive to rapid circulation of the Water, which assures wet tubes, maximum heat transference. and resulting high efficiency and rapidsteaming.

In order to prevent objectionable heating of the furnace walls 8, with injurious effect thereto, we provide adjacent the inner face of each side wall of the furnace a water wall. This water wall comprises a plurality of water tubes consisting of two sets of tubes. The tubes of one set, designated I3, extend from the mud drum 9 adjacent the end thereof, to the drum 1 adjacent the corresponding end ofthe latter. The tubes I3 are of approximately L-shape lengthwise and are disposed reversely to tubes I2, the lower arms of tubes I3 being inclined upward and forward from mud drum 9 and the upper arms of these tubes being disposed substantially vertical and 'extending upward toward drum 1. The end portions of tubes I3 are connected into the drums 'I and 9, the terminal portions of these' tubes being bent so as to enter the drums radially, as is known in the art. Tubes I4 of the other set of tubes of the-water wall connect the mud drum 9 to the y rear upper drum 9. These tubes I4 are of approxlmately U-shape lengthwise and have their bight portions disposed substantially vertical and v parallel to the vertical arms of tubes I3. The tubes I3 and I4 thus form a water wall of approximately rectangular shape and considerable area. It will be noted, from Figure 2, that the upper arms of tubes I2 are disposed between the .water walls and extend transversely of the tubes of the latter at approximately the upper ends of certain of the water wall tubes. It will also be a. combustion space I5 of considerable volume,'this combustion space correspondingl in width Vto thel distance between the water walls and having a height approximately equal to the vertical distance between the mud drum 9 and the front upper drum 1. II'he water walls absorb the radiant heat from the re within the furnace, thus shielding the side walls of the furnace from objectionable heating, while utilizing this radiant heat to best advantage for heating the water.

This results in a boiler of exceptionally high efficiency and capacity, and which steams extile roof I8 extending between the drums 1 and 8.

A tile baiile |1 extends from thetop of bridge wall 3 upward between the two front rows of tubes of bank Il, and a supplemental baille I8 extends upward and forward from the upper end of baille I1, this supplemental baille conveniently resting upon the lower ones of the upper arms of tubes I2. A baille1 9 extends downward from drum 8 centrally of the rear bank of tubes, and a baille 2l), disposed in rear of baffle I9, extends lengthwise of the rear bank of tubes and terminates a short distance from drums 8 and 9. The products of combustion may escape from the furnace through an outlet 2| leading to a breeching and controlled by a damper 22. Y

Steam tubes 23 connect drum 8, at the upper portionthereof, to a steam manifold 24 disposed within drum 1, adjacent the top thereof, and closed to the interior of this drum. A baiile 25 is disposed within drum 8 adjacent the ends of tubes 23. Manifold 24 is connected by steam tubes 26 to manifold 21 of a superheater 28, comprising a second manifold 29 and tubes 30 connecting the manifolds 21 and 29 and" extending downward into the furnace between the tubes of the rear bank, as in Figure 2. Manifold 29 of the superheater is connected to suitable steam take-off means, in a known manner.

Drums 1 and 8 are connected by steam tubes 3| opening into the upper portions of these drums and conveniently disposed in the plane of tubes 23. The respective tubes 23 are of the same cross sectional area as the respective tubes 3|, but the latter tubes are materially greater in number than tubes 23. We find that the total capacity of the tubes 3| should preferably approximate one and one-half times the capacity of the tubes 23. Assuming there to be fourteen of the tubes 23, there should be twenty-one of the tubes 3 I, if the respective tubes 3| are of the same cross-sectional interior area as the respective tubes 23. Since the tubes 23 are materially. less in number than the tubes 3 I, steam header 24, which corresponds approximately in length to the baille 25, extends but approximately one-third of the length of drum 1, as .will be clear from Figure 1.

A baille 32 is disposed within the upper portion of drum 1 and extends across the ends of tubes 3|, and a baille 33 is similarly disposed in drum 8, it being noted that the opening between this latter baille and the wall of the drum is much greater than the opening between baille 32 and f `noted that the tubes l2 and the water Wall define the wan qf drum 1. The bane n is to facilitate separation of moisture from the steam, whereas the baille 32 is to prevent entry of water with the steam from drum 1.

It will be noted that steam can flow readily through the twenty-one tubes 3| from drum 1 into drum 8, whereas flow of steam from the latter drum through the fourteen tubes 23 is relatively reduced. This has the effect of creating within drum 8 a somewhat higher pressure than that which exists within drum 1. being conducive to maintaining the water at the proper level within drums 1 and 8, particularly when the boiler is steaming rapidly. Due to the exceedingly high speed of circulation of the water through the water walls and the banks of water tubes, there is a tendency, in some cases, to pile up the water in drum 8, raising the water level therein to an objectionable extent while objectionably lowering the water level in drum 1. When this occurs, priming is apt to result, and there is also the possibility that water may be withdrawn from the upper portions oi' the tubes connected to drum 1 tosuch an extent as to cause dry tubes, with resulting steam locking and other difficulties. We nd that the possibility of these dilculties arising, under unfavorable conditions, may be avoided by creating a somewhat higher pressure in drum 8 than in drum 1, in the manner above stated) In some instances this may not be necessary, but we prefer creating a difference in pressure between the drums 1 and 8 side wall of said furnace and providing1 a water wall therefor, each of said plurality of tubes com-` prising two sets of tubes, the tubes of one set being of approximately L-shape lengthwise with lower arms connected to and extending upward and forward from said mud drum and substantially vertical upper arms. extending toward and connected to'said front upper drum, the vtubes of the other set connecting said mud drum to said rear upper drum and being of approximately U- shape with their bight portions disposed substantially vertically, a bank of water tubes connecting said two upper drums, a bank of tubes connecting said rear upper drum to said mud drum, and a bank of tubes of approximately L`shape lengthwise connecting said mud drum to said front upper'drum, the lower arms 'of the tubes of the This is desirable as la'st named bank being substantially vertical and front and the back of the furnace, a plurality of tubes disposed in proximity to the inner face of each side wall of said furnace 'and providing a water wall therefor, each of said plurality of tubes comprising two sets of tubes, the tubes of one set being of approximately L-shape lengthwise with lower arms connected to and extending upward and forward from said mud drum and substantially vertical upper arms extending toward and connected to said front upper drum, the tubes of the other set connecting said mud drum to said rear upper drum and being of approximately U- shape with their bight portions disposed substantially vertically, a bank of water tubes connecting said two upper drums, a bank of tubes connecting said rear upper drum tosaid mud drum, and a bank of tubes of approximately L-shape lengthwise connecting said mud drum to said front upper drum, the lower arms of the tubes of the last named bank being substantially vertical and the upper arms thereof ,extending upward and forward between said water walls substantially at the upper ends of the vertical arms of certain of the tubes of said water walls, said last named bank of tubes defining with the water walls a box like combustion space and the upper arms of the tubes of said last named bank being alternately depressed and forming a slag screen over said space.

3. In a boiler of the character described, a front upper drum, a rear upper drum, a lower mud drum, a bank of water tubes connecting said two upper drums, a bank of tubes connecting said rear upper drum to said mud drum, a plurality of tubes adjacent each end of said drums denning water walls, each of said plurality of tubes comprising two sets of tubes, the tubes -of one set being of approximately L-shape lengthwise with lower arms connected to and extending upward and forward from said mud drum and substantially vertical arms extending toward vand 'connected to said front upper drum, the tubes of the other set connecting said mud drum to said 'rear upper drum and being of approximately U- shape with their bight portions disposed substan- ,mately L-shape lengthwise connecting said mud drum to said front upper drum, the lower arms of the tubes of the last named bank being substantially vertical and the upper arms thereof extending upward and forward between said water walls substantially at the upper ends of the vertiiscal arms of certain of the tubes of said water wal 4. In a boiler of the character described, a front upper steam and water drum, a rear upper steam and water drum, a lower mud drum, banks flow circuit, water walls adjacent the ends of said drums each comprising two sets of water tubes, the tubespf one set connecting said mud drum to said fron* upper drum and the tubes of the other set connecting said mud drum to said rear upper drum, a plurality of steam tubes connecting said -two upper drums, and a plurality of steam take-off tubes connected to said upper rear drum and of materially less total capacity than the steam tubes connecting said two upper drums.

5. In a boiler of the character described, a front upper steam and water drum, a rear upper steam and water drum, a lower muddrum, banks 'of water tubes connecting said drums in a ring flow circuit, water walls adjacent the ends of said drums each comprising two sets of water tubes, the tubes of one set connecting said mud drum to said front upper drum and the tubes of the other set connecting said mud drum to said rear upper drum, a plurality of steam tubes connecting said two upper drums, a steam header within said front upper drum and closed to the interior thereof, a plurality` of steam tubes connecting said rear upper drum to said header and of materially less total capacity than the steam tubes connecting said two upper drums, and steam take-off means connected to said header.

6. In a boiler of the character described, a front upper steam and Water drum, a rear upper steam and water drum, a lower mud drum, banks of water tubes connecting said drums in a ring flow circuit, water walls adjacent the ends of said `drums each comprising two sets of water tubes.

the tubes of one set connecting said mud drum to said front upper drum and the tubes of the e other set connecting said mud drum to said rear tially vertically, and a bank of tubes of approxiupper drum, a plurality ofsteam tubes connecting said two upper drums, a steam header within said front upper drum and closed to the interior thereof, a yplurality of steam tubes connecting said rear upper drum to said header and of materially less total capacity than the steam tubes connecting said two upper drums, 'and a superheater connected to said header.

GEORGE W. H EALD. AUDREY J. POPHAM.

of water tubes connecting said drums in a ring I 

